They also came up against a goalkeeper at the top of his game in Swansea's Polish number one Lukasz Fabianski.

The only goal came against the run of play in the 41st minute when Mawson swept the ball in at corner and Virgil van Dijk had misplaced a header as he tried to clear.

It summed up an awkward league debut for Van Dijk, who had previously only played in one FA Cup tie since his record £75 million move from Southampton.

'He probably has season ticket'

The frustrations provoked Klopp into his argument with a Swansea supporter around the hour mark and he admitted: "He was shouting at me all the time but I reacted. I am a human being, not just a professional manager.

"I am sure I am not the first manager who has a problem. He probably has a season ticket."

Klopp added: "Swansea knew that to win today they needed our help and unfortunately we gave it to them.

“They did the right things to deserve to win a game like this tonight and we didn’t deserve it.

"We could have equalised at the end, but didn’t have that luck."

For new Swans manager Carlos Carvalhal, this was a tactical triumph as he used a five-man defence to deny Liverpool space and then hit them on the break.

The Portuguese likes to use seafood metaphors to describe players as either lobsters or sardines, but this time he was borrowing motor racing analogies as he left Liverpool on the hard shoulder.

Carvalhal said: “I talked with my players and said this (Liverpool) is a really strong team.

“They are like a Formula One car. But at 4:00 pm in London it will be difficult to speed, they would be a car like any other.

“We needed to make sure there was traffic, we could not let them have open roads to drive in."